Four inbred lines of honey bees ( Apis mellifera L.) were analyzed for weight differences. Two lines were compared with their F[1][1] hybrids. A highly significant difference was shown between the inbred lines and between the inbred lines and their F[1][1] hybrids; this indicates heterosis for body weight in the lines used. A proportional relationship of body weight to number of ovarian tubules is shown; the correlation between these variables is highly significant. [1]: #fn-1